Lake County, Indiana

Lake County is a county in Indiana, United States, in the state’s far northwest corner against the Illinois line and the Lake Michigan shore, about 25 miles southeast of downtown Chicago. It had a population of 498,700 at the 2020 census, an estimated 504,612 more recently, and covers 626.56 square miles (1,622.8 km2) centred near 41°25′N 87°22′W.

Crown Point is the county seat; its postal code is 46307. The county holds 7 cities, 12 incorporated towns and a scatter of smaller unincorporated communities across 11 townships, and unlike the rest of Indiana it runs on Central Time.

Towns & Villages in Lake County

Lake County has 19 incorporated cities and towns, Indiana’s second-highest count after Marion County, plus one large census-designated place and roughly a dozen smaller unincorporated crossroads communities with no government of their own. CDP stands for census designated place; Unincorp. covers communities with no formal boundary or local government.

Lakes of the Four Seasons is the county’s one large CDP, but the Lake–Porter county line runs directly through the middle of it: the population above is the whole community, and only the Winfield Township half, gated by Big Bass Lake and Lake Holiday, sits in Lake County. Beyond the places listed here, roughly a dozen smaller unincorporated crossroads — Ainsworth, Belshaw, Brunswick, Leroy, Liverpool, Ross, Shelby and Lake Dalecarlia among them — are named on county maps with no separate population count.

Townships

Lake County’s 11 civil townships mostly correspond to a single city or town apiece, a legacy of the industrial cities that grew large enough to fill their township outright.

ZIP Codes

• 46402 — Gary (also serves 46403, 46404, 46406, 46407, 46408 and 46409; 46401 is a Gary PO box code)
• 46320 — Hammond (also serves 46323, 46324 and 46327; 46325 is a Hammond PO box code)
• 46307 — Crown Point (also serves Lakes of the Four Seasons; 46308 is a Crown Point PO box code)
• 46410 — Merrillville (also serves the 46411 PO box code)
• 46342 — Hobart
• 46312 — East Chicago
• 46405 — Lake Station
• 46394 — Whiting
• 46375 — Schererville
• 46322 — Highland
• 46321 — Munster
• 46373 — St. John
• 46319 — Griffith
• 46311 — Dyer
• 46303 — Cedar Lake
• 46356 — Lowell
• 46376 — Schneider (PO box only, no residential delivery route)

Winfield and New Chicago have no ZIP code of their own; mail addressed there is delivered under Crown Point’s 46307 and Hobart’s 46342 codes respectively.

Geography

Lake County sits at Indiana’s northwest tip, where the state’s dune-and-swale shoreline meets Illinois. Of its 626.56 square miles, 498.96 are land and 127.60 are water, a share far higher than most Indiana counties, driven by the county’s stretch of Lake Michigan and by Wolf Lake and George Lake along the state line. Indiana Dunes National Park extends into the county’s northern edge along the lakeshore near Portage, and the Little Calumet and Grand Calumet rivers thread through the industrial north end before reaching the lake.

Porter County lies east, Jasper County south, and Newton County southwest, all within Indiana. Illinois’ Cook, Will and Kankakee counties border Lake County to the west and southwest, and Lake Michigan forms the entire northern edge. Porter County and Cook County, Will County and Kankakee County in Illinois all touch Lake County directly; Jasper and Newton counties do not currently have their own pages on this site.

Demographics

Lake County had a population of 498,700 at the 2020 census, and the latest Census Bureau estimate puts the county near 504,612 residents, essentially flat after decades of decline from an industrial-era peak above 546,000 in 1970. Hammond and Gary are the two largest cities, together holding more than a quarter of the county’s population, though Gary’s own count has fallen sharply from its mid-century steel-boom high. Median household income runs $71,493, close to Indiana’s statewide figure of $69,477. Population density works out to about 1,000 people per square mile of land, among the highest in Indiana outside the Indianapolis area, reflecting the county’s place inside the Chicago metropolitan area.

Economy & Local Life

Health care and social assistance employs the most workers in the county, about 35,560 people, followed by manufacturing at 33,245 and retail trade at 25,454. Manufacturing still centers on steel: U.S. Steel’s Gary Works and Cleveland-Cliffs’ Indiana Harbor works in East Chicago remain among the largest integrated steel mills in North America, and the BP Whiting Refinery, one of the largest oil refineries in the country, anchors Whiting’s economy. Community Hospital in Munster and Methodist Hospitals across Gary and Merrillville are major health care employers, and Purdue University Northwest’s Hammond campus and Indiana University Northwest in Gary are the county’s principal four-year colleges. Horseshoe Casino Hammond and the newer Hard Rock Casino Northern Indiana in Gary draw visitors from across the Chicago area. The county’s biggest annual event is the Lake County Fair, held in Crown Point each August.

History

Lake County was organized on 16 February 1837, carved from Newton County and named for its frontage on Lake Michigan. The Potawatomi lived across the area before removal in the 1830s. The county stayed thinly settled and largely agricultural until the early 1900s, when Inland Steel opened a plant at East Chicago in 1903 and U.S. Steel founded the company town of Gary in 1906, drawing waves of immigrant labor from Europe and, later, Black workers from the South in the Great Migration. The steel and oil industries pushed the county’s population past half a million by mid-century, peaking near 546,000 in 1970 before decades of mill closures and downsizing set off a long decline that only leveled off in recent years.

Getting There

Interstates 65, 80, 90 and 94 all cross Lake County, converging near Gary and Hammond in one of the busiest interchange clusters in the Midwest; I-90 through the county is the tolled Indiana Toll Road / Chicago Skyway approach.

• Chicago, Illinois — about 5 miles northwest of Hammond
• Valparaiso — about 15 miles east
• South Bend — about 70 miles east
• Indianapolis — about 150 miles south

Gary/Chicago International Airport, inside the county, offers limited scheduled service; most residents fly from Chicago Midway International Airport, about 20 miles northwest, or O’Hare International Airport, about 30 miles northwest. There is no Amtrak stop in the county; the nearest is Michigan City in neighboring LaPorte County. The South Shore Line, a commuter railroad, stops at multiple Lake County stations, including Hammond, East Chicago and Gary, and runs directly into downtown Chicago.

Frequently Asked Questions

Where is Lake County, Indiana located?
It sits at Indiana’s northwest corner on Lake Michigan, bordering Illinois’ Cook, Will and Kankakee counties and Indiana’s Porter, Jasper and Newton counties.

What is the population of Lake County?
498,700 at the 2020 census, with a recent estimate near 504,612, making it Indiana’s second-most populous county after Marion.

How big is Lake County?
626.56 square miles (1,622.8 km2), of which 498.96 square miles are land and the rest is water, mostly Lake Michigan.

What is the county seat of Lake County?
Crown Point, a city of 33,899 people in Center Township.

How many towns and cities are in Lake County?
19 incorporated places — 7 cities and 12 towns — plus the CDP Lakes of the Four Seasons and about a dozen smaller unincorporated communities.

What ZIP codes does Lake County use?
Roughly 30 codes in total, led by the 464xx series for Gary, Hammond, Crown Point, Merrillville and the county’s other cities and towns.

What is Lake County known for?
Its steel industry — U.S. Steel’s Gary Works and the BP Whiting Refinery — its place in the Chicago metropolitan area, and its stretch of Indiana Dunes National Park along Lake Michigan.

More counties in this state: Towns and villages in Indiana.